1. Field of the Invention
The present invention relates to vehicle cargo reminders and, more particularly, to a non-intrusive cargo reminder having an alarm triggered by a change in acceleration of the vehicle.
2. Description of the Related Art
It is not an uncommon occurrence for drivers of vehicles transporting roof-mounted cargo, towing high profile trailers, or simply having an oversized height to be involved in accidents in which an overhead obstruction is hit because the driver was unaware, or forgot, about the cargo being transported, or the characteristics of the vehicle being driven or of the trailer being towed.
Examples of devices designed to remind a driver of cargo being transported include a drop down flag or sign attached to a garage door that hangs down when the garage door is opened. Another is a spring-loaded magnetic device with a popup warning that the driver attaches to the hood of his or her car. When the car is driven at speeds above a certain minimum, wind resistance forces the spring-loaded warning down from the view of the driver. When the speed of the car falls below the minimum value, the popup warning is brought up by the action of a spring or other similar actuator. Several problems exist with both of these systems. The first device is limited to warn the driver only when parking a car in the garage installed with the device. Both the first and second devices have to be disabled manually by the driver when no cargo is being transported.
U.S. Pat. No. 6,737,960, issued on May 18, 2004, discloses an automatic reminder alarm for a recreational equipment vehicle rack having a transmitter placed in proximity of a garage, a receiver located inside the car, an alarm connected to and triggered by the receiver, and an actuating device that automatically activates the receiver when recreational equipment is mounted in the vehicle rack. The receiver triggers the alarm when it is in range of the transmitter and the actuator has activated the receiver. The high cost associated with the need for two transducers, i.e., a receiver and an actuating device, makes this system unattractive. In addition, the need to have a transducer located outside of the vehicle is also unappealing.
U.S. Pat. No. 5,389,912, issued on Feb. 14, 1995, illustrated a truck clearance anti-collision system that uses an ultrasonic wave transmitter and an ultrasonic wave receiver for receiving waves generated by the ultrasonic wave transmitter reflected off an object disposed vertically above the vehicle. The device is mountable on a portion of a vehicle for transmitting substantially vertical ultrasonic waves. A computer device operatively associated with the ultrasonic wave transmitter and receiver calculates the vertical difference between the object and the height of the truck and provides human-recognizable information to the operator of the truck as to the vertical clearance available between the object and an uppermost portion of the vehicle. The cost of this system is also relatively high because of the different transducers needed and the need for professional installation and maintenance.
An overhead warning detector is disclosed in U.S. Pat. No. 5,424,713, issued on Jun. 13, 1995. The disclosed detector includes a terminal box positioned on top of a truck cab. The terminal box has a rotating member having a vertically extending antenna, or feeler. The antenna or feeler is adjustable in height to an elevation corresponding to the elevation of the highest point of the trailer of the truck. A control panel connected to the terminal box has an alarm that is actuated when the rotating member is turned when the vertically extending member contacts an obstacle having a clearance lower than the highest point of the trailer. Such a system is cumbersome to use because the user has to physically adjust the height of the vertically extending antenna each time the maximum height of the vehicle changes.
Therefore, in view of the above-noted brief summary of prior art inventions and their associated limitations, a need exists for an inexpensive cargo warning system that requires no professional installation, no external transducers, and little maintenance.